Cable modem termination system having a gateway for transporting out-of-band messaging signals

ABSTRACT

A Cable Modem Termination System (CMTS,  42 , FIG.  1 ) having a gateway configured to output signals over tunnels, wherein the tunnels are one way and out-of-band messages (FIG.  1 ) are sent over said tunnels (FIG.  1 ).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT application Ser. No.PCT/US2004/028909 filed Sep. 7, 2004, which claims the benefit of U.S.provisional application Ser. No. 60/501,231 filed Sep. 5, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to Cable Modem Termination Systems (CMTSs)of the type having a gateway for transporting out-of-band (OOB)messaging signals.

2. Background Art

A cable modem termination system (CMTS) is generally a system located ata headend or other location of a cable service provider for transportingdata packets from one location to another, such as between an internetservice provider (ISP) and a subscriber station. In particular, the CMTSmay be configured for downstream communication such that it isconfigured to receive IP packets from the ISP, to convert the IP packetsto digital cable packets, and to deliver the digital cable packets tothe subscriber station. In addition, the CMTS may be configured forupstream communication such that it is configured to receive digitalcable packets from the subscriber station, to convert the digital cablepackets to IP packets, and to deliver the IP packets to the ISP.

A need exists for a CMTS to include capabilities for transporting OOBmessaging signals.

SUMMARY OF THE INVENTION

The present invention contemplates a number of features andconfigurations for the CMTS, including the CMTS having a gatewayconfigured to output signals on at least two types of data tunnels fortransfer over a cable network to Customer Premises Equipment (CPE). Eachdata tunnel is preferably characterized as a one-way data stream ofout-of-band (OOB) messaging signals and each type of data tunnel ispreferably associated with a different type of OOB messaging signalssuch that different types of data tunnels transfer different types ofOOB messages.

In one aspect of the present invention, the system includes a CMTSconfigured to include a gateway configured to output signals on aplurality of data tunnels for transfer over a cable network to CustomerPremises Equipment (CPE). Each data tunnel is preferably characterizedas a one-way data stream of out-of-band (OOB) messaging signals. TheCMTS preferably includes a plurality of output ports for transferringthe OOB messaging signals from the gateway to the cable network, whereineach output port is capable of transferring different types of OOBmessaging signals.

The above features and advantages, along with other features andadvantages of the present invention, are readily apparent from thefollowing detailed description of the invention when taken in connectionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a cable system in accordance with one aspect of thepresent invention;

FIG. 2 illustrates Customer Premises Equipment (CPE) in accordance withone aspect of the present invention;

FIG. 3 illustrates a Cable Modem Termination System (CMTS) in accordancewith one aspect of the present invention;

FIG. 4 illustrates an interface of the CMTS in accordance with oneaspect of the present invention;

FIG. 5 illustrates a data tunnel in accordance with one aspect of thepresent invention; and

FIG. 6 illustrates a Downstream Channel Descriptor (DCD) message inaccordance with one aspect of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIG. 1 illustrates a cable system 10 in accordance with one aspect ofthe present invention. The system 10 includes a management network 12and a High Speed Data (HSD) network 14 that respectively providemanagement and HSD services over a hybrid fiber coax (HFC) 18, or othercommunication medium, to a subscriber station 20, which includesCustomer Premises Equipment (CPE) 22 and a cable modem (CM) 24.

The management network 12 generally comprises two portions, a controlportion 30 and an application portion 32. The control portion 30includes a settop box (STB) controller to control, provision, manage,and secure the CPE 22 through out-of-band (OOB) messaging. Theapplication portion 32 provides applications to the CPE 22, such asvideo on demand (VOD), interactive television (iTV), and other services.

The HSD network 14 provides data services for the system 10, includingservices for the CM 24 to access the Internet 36. It includes a networkprovisioning unit (NPU) 38 having capabilities for Dynamic HostConfiguration Protocol (DHCP), Trivial File Transfer Protocol (TFTP),and the like, in addition to a Domain Name System (DNS) server.

The system 10 includes a cable modem termination system (CMTS) 42 tosend and receive signals to and from the CPE 22 and the CM 24 over theHFC 18. In general, the CMTS 42 transfers IP packets from the HSDnetwork 14 and the management network 12 to the CPE 22 and CM 24 forprocessing. Preferably, the signals are outputted from the CMTS 42 ondownstream output channels, which preferably include one-way output datatunnels, such as for OOB messaging. In addition, the CMTS 42 isconfigured to receive signals from the CPE 22 and the CM 24 to supporttwo-way communication therewith, such as for transfer of IP packets fromthe CPE 22 and/or the CM 24 to the Internet 36 and/or the VOD or STBcontroller portions 32 and 30.

The system 10 includes a conditional access router (CAR) 46 to connectthe management network 12 to the CMTS 42. The CAR 46 transports signalstherebetween using IP protocols and provides firewall separation for theVOD or STB controller portions 32 and 30 from the HSD network 14,enhancing security from any devices attempting to associate with devicesand signaling on the management network 12. In operation, signalingtraffic transported between the management network 12 and the CMTS 42may be wrapped into addressable packets, such as Ethernet, IP, or otherpackets.

The system 10 includes a video unit 50 for delivering video signals tothe subscriber station 20 over the HFC 18. The video unit 50 can deliverany number of video signals, including network television, cabletelevision, pay-per-view, video on demand, and the like.

FIG. 2 illustrates the CPE 22 in accordance with one aspect of thepresent invention. The CPE 22 is preferably configured to communicatewith the CMTS 42 through digital cable signals, such as throughsignaling defined by the Data Over Cable Service Interface Specification(DOCSIS) and/or through other protocols authorized through DHCPregistration.

The CPE 22 includes a radio frequency (RF) splitter 60, an embeddedcable modem (eCM) 62, an embedded set-top box (eSTB) 64, an audio visual(A/V) port 66, and an optional conditional access (CA) unit 68. The RFsplitter 60 splits the RF signal into two portions—one for OOB controlfunctions and two-way application traffic and one for video delivery.The OOB and two-way application traffic is relayed to the eCM 62 and thevideo is relayed to the eSTB 64.

The eSTB 64 outputs video and other media signals to a media outputdevice (not shown) or other device connected to the A/V port 66, such asto a television (TV), digital video recorder (DVR), personal videorecorder (PVR), or the like.

The eCM 62 processes control and other non-media signals, such as DOCSISand other IP packets, and bridges or relays the signals to the eSTB 64through an internal communications link 70. In particular, thecommunications link 70 is used to transfer data tunnels tuned to by theeCM 62 to the eSTB 64 so that OOB messaging signals can be delivered tothe eSTB 64 for processing.

The CA unit 68 provides conditional access control for the subscriberstation 20. It can be a CableCard, SmartCard, or other item forcontrolling security and access to the data, video, and control signalstransmitted over the HFC 18. It is illustrated as a standalone item,however, it can be included with or embedded on the eSTB 64 or the eCM62 to perform similar functions.

The eCM 62, eSTB 64, and CA unit 68 are logically separate entities,however, they may physically share hardware and software. Other items,such as control logic and applications may be included on the CPE 22 forcontrolling operation of the eSTB 64 and/or the eCM 62.

FIG. 3 illustrates the CMTS 42 in accordance with one aspect of thepresent invention. The CMTS 42 includes a first interface 80 and asecond interface 82 for sending and receiving signals to and from themanagement and HSD networks 12, 14, respectively. The CMTS 42 furtherincludes a third interface 86 for sending and receiving signals to andfrom the CPE 22 and CM 24 over the HFC 18. A processor 90, which is incommunication with a memory 92, processes the signals for communicationwith the first, second, and third interfaces 80, 82, 86 according toinstructions stored on the memory 92.

FIG. 4 illustrates the third interface 86 in accordance with one aspectof the present invention. The third interface 86 includes a number ofblades, referred to with reference numerals 96-102, which each include anumber of output ports, referred to with reference numerals 106-120, anda number input ports, referred to with reference numerals 126-140. Theblades 96-102 may be removable items, such as cards. The input ports126-140 receive signals from the CPE 22 and the CM 24 and the outputports 106-120 send signals to the CPE 22 and the CM 24. The ports106-140 are preferably radio frequency (RF) ports. The third interface86 can include any number of blades 96-102 and any number of input andoutput ports 106-140 without deviating from the scope and contemplationof the present invention.

The CMTS 42 may be configured to output and receive any number of datastreams over the ports 106-140, including OOB messaging signals, HSDsignals, management layer signals, video signals, and other signals. TheCMTS 42 may be configured to support multiple data streams through timeor frequency division multiplexed for delivery to the CPE 22 and CM 24.In this manner, multiple data streams may be included on the HFC 18 tofacilitate communication with the CPE 22 and the CM 24. Each output port106-120 is preferably separately configurable such that each output portmay output different OOB messaging signals. In this manner, each blade96-102 may include output ports having the same or different OOBmessaging signals.

FIG. 5 illustrates data outputted from one of the output ports 106 inaccordance with one aspect of the present invention. Preferably, OOBmessaging signals are outputted on data tunnels 150 that are one-waydata streams and include instructions to provision, manage, and securethe CPE 22, and which are delivered from the CMTS 42 to the eCM 62according to protocols defined in the DOCSIS. The OOB messaging signalsmay assigned to different tunnel types, such as a common broadcasttunnel type 154, a conditional access tunnel type 156, an applicationdata tunnel type 158, a code download tunnel type 160, and an othertunnel type 162. The broadcast tunnel 154 may be used to communicatesignals for multiple subscriber stations 20, such as Emergency AlertSystem (EAS) signals and other standardized messages. The conditionalaccess tunnel 156 may be use to communicate entitlement managementmessages and the like. The application tunnel 158 may be used tocommunicate program guide data, such as for electronic programmingguides (EPGs). The code download tunnel 160 may be used to deliver newoperating codes and updates to the subscriber station 20.

Referring to FIG. 6, each tunnel type 182 is preferably associated witha unique network address 184, such as a media access control access(MAC) address. The MAC address of each tunnel type 182 may be used bythe CPE 22 or other downstream device to locate desired tunnels 154-162.A downstream channel descriptor (DCD) message 180, as shown in FIG. 6,may be outputted over a management layer data stream 166 (FIG. 5), whichis preferably separate from the data tunnels 150, for mapping orassociating the different tunnel types 182 with their network addresses184 so that devices located downstream thereof may interpret the DCDmessage 180 to located desired tunnel types 182.

FIG. 6 illustrates a diagram of the DCD message 180 in accordance withone aspect of the present invention. The illustrated DCD message 180 isin a table format, however, the message 180 may have any form. Itincludes a tunnel type column 182, a network address column 184, and atunnel identifier column 186. The tunnel type column 182 identifies thetunnel types of the tunnels identified in the DCD message 180. Thenetwork address 184 associated with the tunnel types 182 are shown inthe network address column 184. Tunnel identifiers 186 associated withthe network address 184 are shown in the tunnel identifier column 186.The tunnel identifiers 186 are unique identifiers associated with eachtunnel type 182. The tunnel types 182 are common identifiers, i.e.broadcast, conditional access, application, etc, such that the same DCDmessage 180 or different DCD message 180 may include the same tunneltype. In contrast, the tunnel identifier 186 is a unique identifier foreach tunnel 154-162, regardless of the tunnel type 182 assigned to thetunnel 154-162, such that the tunnel identifier 186 may be used todifferentiate between different tunnels 1542-162 identified with thesame tunnel type 182. For example, the CMTS 42 may be required tosupport CPEs 22 of different vendors such that each vendor requires aparticular set of conditional access signals. In this case, theconditional access signals are provided through different conditionalaccess tunnels 156, whereby each conditional access tunnel 156 isidentifiable by the tunnel identifier 186 associate therewith. In thismanner, multiple conditional access tunnels 156 may be used within thesystem 10 and assigned to different CA units 68 based on the uniquetunnel identifier 186, which is preferably referred to as itsconditional access identification.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

1. A gateway comprising: a processor; and a memory having stored thereincomputer executable instructions, that when executed by the processor,cause the gateway to perform a method of: transmitting signals on atleast two types of data tunnels for transfer over a network to CustomerPremises Equipment (CPE), each data tunnel characterized as a one-waydata stream of out-of-band (OOB) messaging signals, where each type ofdata tunnel is associated with a different type of OOB messaging signalsuch that different types of data tunnels transfer different types ofOOB messages: and transmitting a downstream channel descriptor (DCD)with a tunnel type, network address, and tunnel type identifier forassociating the different types of data tunnels with network addressesand wherein two different tunnels of the same tunnel type have differenttunnel type identifiers.
 2. The gateway of claim 1 wherein the methodfurther performs: transmitting the OOB messaging signals on at leastfour types of data tunnels.
 3. The gateway of claim 1 wherein at leastone of the types of data tunnels is a broadcast tunnel.
 4. The gatewayof claim 1 wherein at least one of the types of data tunnel is aconditional access tunnel.
 5. The gateway of claim 1 wherein at leastone of the types of data tunnels is an application tunnel.
 6. Thegateway of claim 1 wherein at least one of the types of data tunnels isa code download tunnel.
 7. The gateway of claim 1 wherein the methodfurther performs: transmitting the data streams of the data tunnels ontothe network on a plurality of output ports in communication with thegateway, wherein each output port includes at least two types of datatunnels.
 8. The gateway of claim 7 wherein a first and a second one ofthe plurality of output ports are associated with different types of OOBmessaging signals.
 9. The gateway of claim 8 further comprising aplurality of blades, each blade including one or more output ports. 10.The gateway of claim 9 wherein the first and second output ports arelocated on the same blade.
 11. The gateway of claim 9 wherein the firstand second output ports are located on different blades.
 12. The gatewayof claim 1 wherein each data tunnel is identified with a networkaddress.
 13. The gateway of claim 1 wherein the OOB messaging signalsare transmitted according to protocols defined in a Data Over CableService Interface Specification (DOCSIS).
 14. The gateway of claim 1wherein the CPE is a settop box.
 15. The gateway of claim 1 wherein theCPE includes an embedded cable modem (eCM) and an embedded settop box(eSTB).
 16. The gateway of claim 15 wherein the 00B messaging signalsare transferred to the eCM.
 17. A cable modem termination system (CMTS),the CMTS comprising: a gateway configured to output signals on aplurality of data tunnels for transfer over a network to CustomerPremises Equipment (CPE), each data tunnel characterized as a one-waydata stream of out-of-band (OOB) messaging signals; and a plurality ofoutput ports for transferring the OOB messaging signals from the gatewayto the network, wherein each output port is capable of transferringdifferent OOB messaging signals, wherein the CMTS outputs a downstreamchannel descriptor (DCD) with a tunnel type, network address, and tunneltype identifier for associating the different types of data tunnels withnetwork addresses and wherein two different tunnels of the same tunneltype have different tunnel type identifiers.
 18. The CMTS of claim 17wherein each output port includes at least two types of data tunnels.19. The CMTS of claim 17 wherein a first and a second one of theplurality of output ports are associated with different OOB messagingsignals.
 20. The CMTS of claim 19 further comprising a plurality ofblades, each blade including one or more output ports.
 21. The CMTS ofclaim 20 wherein the first and second output ports are located on thesame blade.
 22. The CMTS of claim 20 wherein the first and second outputports are located on different blades.
 23. A method comprising:receiving data services information from a data network; receivingout-of-band signals and application data from a management network;processing the data services information, out-of-band signals, andapplication data for transmission; and transmitting the data servicesinformation, out-of-band signals, and application data to CustomerPremises Equipment (CPE) on two-way output channels and a plurality ofdifferent types of one-way output data tunnels, each different type ofout-of-band signal sent on a different type of data tunnel; andoutputting a downstream channel descriptor (DCD) with a tunnel type,network address, and tunnel type identifier for associating thedifferent types of data tunnels with network addresses wherein twodifferent tunnels of the same tunnel type have different tunnel typeidentifiers.
 24. The method of claim 23, wherein processing the dataservices information, out-of-band signals, and application datacomprises converting them from IP packets into digital cable packets.25. The method of claim 23, further comprising receiving digital cablepackets from a subscriber station.
 26. The method of claim 25, furthercomprising converting the digital cable packets to IP packets.
 27. Themethod of 26, further comprising transmitting the IP packets to aninternet service provider.
 28. The method of claim 23, wherein thetunnel type is a common broadcast tunnel.
 29. The method of claim 23,wherein the tunnel type is a conditional access tunnel.
 30. A methodcomprising: receiving video signals, data services information,out-of-band signals, and application data at Customer Premises Equipment(CPE) on two-way output channels and on a plurality of one-way datatunnels, each different type of out-of-band signal received on adifferent type of data tunnel; receiving a downstream channel descriptor(DCD) with a tunnel type, network address, and tunnel type identifierfor associating the different types of data tunnels with networkaddresses wherein two different tunnels of the same tunnel type havedifferent tunnel type identifiers; transmitting the data servicesinformation and out-of-band signals to one or more devices with cablemodem functionality; and transmitting the application data and videosignals to one or more devices with set-top box functionality.
 31. Themethod of claim 30, wherein the communication of the video signals, dataservices information, out-of-band signals, and application data isdefined by the Data Over Cable Service Interface Specification (DOCSIS).32. The method of claim 30, wherein the one or more devices with set-topbox functionality outputs the video signals and other media signals to amedia output device.
 33. The method of claim 30, wherein the one or moredevices with cable modem functionality processes the out-of-band signalsand other non-media signals.
 34. The method of claim 33, wherein the oneor more devices with cable modem functionality further transmits theout-of-band and the other non-media signals to the one or more deviceswith set-top box functionality via an internal communications link forprocessing.
 35. The method of claim 30, further comprising providingconditional access control for the subscriber station.
 36. An apparatuscomprising: a processor; a memory having stored therein computerexecutable instructions, that when executed by the processor, cause theapparatus to perform a method of: receiving video signals, data servicesinformation, out-of-band signals, and application data at CustomerPremises Equipment (CPE) on two-way output channels and on a pluralityof one-way data tunnels, each different type of out-of-band signalreceived on a different type of data tunnel; receiving a downstreamchannel descriptor (DCD) with a tunnel type, network address, and tunneltype identifier for associating the different types of data tunnels withnetwork addresses and wherein two different tunnels of the same tunneltype have different tunnel type identifiers; transmitting the dataservices information and out-of-band signals to one or more devices withmodem functionality; and transmitting the application data and videosignals to one or more devices with set-top box functionality.
 37. Theapparatus of claim 36, wherein the communication of the video signals,data services information, out-of-band signals, and application data isdefined by the Data Over Cable Service Interface Specification (DOCSIS).38. The apparatus of claim 36, wherein the one or more devices withset-top box functionality outputs the video signals and other mediasignals to a media output device.
 39. The apparatus of claim 36, whereinthe one or more devices with cable modem functionality processes theout-of-band and other non-media signals.
 40. The apparatus of claim 39,wherein the one or more devices with cable modem functionality furthertransmits the out-of-band and the other non-media signals to the one ormore devices with set-top box functionality via an internalcommunications link for processing.
 41. The apparatus of claim 36, wherethe method further performs providing conditional access control for thesubscriber station.
 42. A gateway comprising: a processor; and a memoryhaving stored therein computer executable instructions, that whenexecuted by the processor, cause the gateway to perform a method of:transmitting signals on at least two types of data tunnels for transferover a network to Customer Premises Equipment (CPE), each data tunnelcharacterized as a one-way data stream of out-of-band (OOB) messagingsignals, wherein each type of data tunnel is associated with a differenttype of OOB messaging signal such that different types of data tunnelstransfer different types of 00B messages and wherein a media accesscontrol (MAC) address of each tunnel type is used by the CPE to locate adesired tunnel; and transmitting a downstream channel descriptor (DCD)with a tunnel type, network address, and tunnel type identifier forassociating the different types of data tunnels with network addressesand wherein two different tunnels of the same tunnel type have differenttunnel type identifiers.
 43. A method comprising: receiving dataservices information from a data network; receiving out-of-band signalsand application data from a management network; processing the dataservices information, out-of-band signals, and application data fortransmission; and transmitting the data services information,out-of-band signals, and application data to Customer Premises Equipment(CPE) on two-way output channels and a plurality of different types ofone-way output data tunnels, wherein each different type of out-of-bandsignal is sent on a different type of data tunnel and wherein a mediaaccess control (MAC) address of each data tunnel type is used by the CPEto locate a desired data tunnel; and outputting a downstream channeldescriptor (DCD) with a tunnel type, network address, and tunnel typeidentifier for associating the different types of data tunnels withnetwork addresses and wherein two different tunnels of the same tunneltype have different tunnel type identifiers.